refactor: Client.clients & Agent is a Client.

Refs: #616
nodejs · Mar 25, 2021 · 4260bdf · 4260bdf
1 parent b3dd69f
commit 4260bdf
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Showing 4 changed files with 115 additions and 75 deletions.
diff --git a/index.js b/index.js
@@ -2,14 +2,15 @@
 
 const Client = require('./lib/core/client')
 const errors = require('./lib/core/errors')
-const Pool = require('./lib/client-pool')
+const Pool = require('./lib/pool')
 const { Agent, getGlobalAgent, setGlobalAgent } = require('./lib/agent')
 const util = require('./lib/core/util')
-const { InvalidArgumentError, InvalidReturnValueError } = require('./lib/core/errors')
+const { InvalidArgumentError } = require('./lib/core/errors')
 const api = require('./lib/api')
 
 Object.assign(Client.prototype, api)
 Object.assign(Pool.prototype, api)
+Object.assign(Agent.prototype, api)
 
 function undici (url, opts) {
   return new Pool(url, opts)
@@ -25,7 +26,7 @@ module.exports.Agent = Agent
 module.exports.setGlobalAgent = setGlobalAgent
 module.exports.getGlobalAgent = getGlobalAgent
 
-function dispatchFromAgent (requestType) {
+function makeDispatch (fn) {
   return (url, { agent = getGlobalAgent(), method = 'GET', ...opts } = {}, ...additionalArgs) => {
     if (opts.path != null) {
       throw new InvalidArgumentError('unsupported opts.path')
@@ -34,18 +35,12 @@ function dispatchFromAgent (requestType) {
     const { origin, pathname, search } = util.parseURL(url)
     const path = `${pathname || '/'}${search || ''}`
 
-    const client = agent.get(origin)
-
-    if (client && typeof client[requestType] !== 'function') {
-      throw new InvalidReturnValueError(`Client returned from Agent.get() does not implement method ${requestType}`)
-    }
-
-    return client[requestType]({ ...opts, method, path }, ...additionalArgs)
+    return fn.call(agent, { ...opts, origin, method, path }, ...additionalArgs)
   }
 }
 
-module.exports.request = dispatchFromAgent('request')
-module.exports.stream = dispatchFromAgent('stream')
-module.exports.pipeline = dispatchFromAgent('pipeline')
-module.exports.connect = dispatchFromAgent('connect')
-module.exports.upgrade = dispatchFromAgent('upgrade')
+module.exports.request = makeDispatch(api.request)
+module.exports.stream = makeDispatch(api.stream)
+module.exports.pipeline = makeDispatch(api.pipeline)
+module.exports.connect = makeDispatch(api.connect)
+module.exports.upgrade = makeDispatch(api.upgrade)
diff --git a/lib/agent.js b/lib/agent.js
@@ -6,7 +6,8 @@ const EventEmitter = require('events')
 
 const kOnConnect = Symbol('onConnect')
 const kOnDisconnect = Symbol('onDisconnect')
-const kCache = Symbol('cache')
+const kOnDrain = Symbol('onDrain')
+const kClients = Symbol('cache')
 const kFactory = Symbol('factory')
 
 function defaultFactory (origin, opts) {
@@ -24,53 +25,99 @@ class Agent extends EventEmitter {
     }
 
     this[kFactory] = (origin) => factory(origin, opts)
-    this[kCache] = new Map()
+    this[kClients] = new Map()
 
     const agent = this
 
-    this[kOnConnect] = function onConnect (client) {
-      agent.emit('connect', client)
+    this[kOnConnect] = function onConnect (origin, clients) {
+      agent.emit('connect', origin, [...clients, agent])
     }
 
-    this[kOnDisconnect] = function onDestroy (client, err) {
+    this[kOnDrain] = function onDrain (origin) {
+      agent.emit('drain', origin)
+    }
+
+    this[kOnDisconnect] = function onDestroy (origin, clients, err) {
       if (this.connected === 0 && this.size === 0) {
         this.off('disconnect', agent[kOnDisconnect])
-        agent[kCache].delete(this.origin)
+        agent[kClients].delete(this.origin)
       }
 
-      agent.emit('disconnect', client, err)
+      agent.emit('disconnect', origin, [...clients, agent], err)
+    }
+  }
+
+  get connected () {
+    let ret = 0
+    for (const { connected } of this[kClients].values()) {
+      ret += connected
     }
+    return ret
   }
 
-  get (origin) {
-    if (typeof origin !== 'string' || origin === '') {
+  get size () {
+    let ret = 0
+    for (const { size } of this[kClients].values()) {
+      ret += size
+    }
+    return ret
+  }
+
+  get pending () {
+    let ret = 0
+    for (const { pending } of this[kClients].values()) {
+      ret += pending
+    }
+    return ret
+  }
+
+  get running () {
+    let ret = 0
+    for (const { running } of this[kClients].values()) {
+      ret += running
+    }
+    return ret
+  }
+
+  // TODO: get closed ()
+  // TODO: get destroyed ()
+
+  dispatch (opts, handler) {
+    if (!opts || typeof opts !== 'object') {
+      throw new InvalidArgumentError('opts must be an object.')
+    }
+
+    if (typeof opts.origin !== 'string' || opts.origin === '') {
       throw new InvalidArgumentError('Origin must be a non-empty string.')
     }
 
-    let pool = this[kCache].get(origin)
+    let pool = this[kClients].get(opts.origin)
 
     if (!pool) {
-      pool = this[kFactory](origin)
+      pool = this[kFactory](opts.origin)
         .on('connect', this[kOnConnect])
         .on('disconnect', this[kOnDisconnect])
+        .on('drain', this[kOnDrain])
 
-      this[kCache].set(origin, pool)
+      this[kClients].set(opts.origin, pool)
     }
 
-    return pool
+    return pool.dispatch(opts, handler)
   }
 
+  // TODO: close (callback)
   close () {
     const closePromises = []
-    for (const pool of this[kCache].values()) {
+    for (const pool of this[kClients].values()) {
       closePromises.push(pool.close())
     }
     return Promise.all(closePromises)
   }
 
+  // TODO: destroy (err, callback)
   destroy () {
     const destroyPromises = []
-    for (const pool of this[kCache].values()) {
+    for (const pool of this[kClients].values()) {
       destroyPromises.push(pool.destroy())
     }
     return Promise.all(destroyPromises)
@@ -80,7 +127,7 @@ class Agent extends EventEmitter {
 let globalAgent = new Agent({ connections: null })
 
 function setGlobalAgent (agent) {
-  if (!agent || typeof agent.get !== 'function') {
+  if (!agent || typeof agent.dispatch !== 'function') {
     throw new InvalidArgumentError('Argument agent must implement Agent')
   }
   globalAgent = agent

diff --git a/lib/core/client.js b/lib/core/client.js
@@ -213,15 +213,6 @@ class Client extends EventEmitter {
     return this[kQueue].length - this[kRunningIdx]
   }
 
-  get busy () {
-    const socket = this[kSocket]
-    return (
-      (socket && (socket[kReset] || socket[kWriting])) ||
-      (this.size >= (this[kPipelining] || 1)) ||
-      this.pending > 0
-    )
-  }
-
   get destroyed () {
     return this[kDestroyed]
   }
@@ -242,6 +233,10 @@ class Client extends EventEmitter {
   }
 
   dispatch (opts, handler) {
+    if (opts.origin && opts.origin !== this.url.origin) {
+      throw new InvalidArgumentError('origin')
+    }
+
     try {
       const request = new Request(opts, handler)
       if (this[kDestroyed]) {
@@ -269,6 +264,8 @@ class Client extends EventEmitter {
 
       handler.onError(err)
     }
+
+    return this[kNeedDrain] > 0
   }
 
   close (callback) {
@@ -484,7 +481,7 @@ class Parser extends HTTPParser {
     detachSocket(socket)
     client[kSocket] = null
     client[kQueue][client[kRunningIdx]++] = null
-    client.emit('disconnect', client, new InformationalError('upgrade'))
+    client.emit('disconnect', [client], new InformationalError('upgrade'))
 
     try {
       request.onUpgrade(statusCode, headers, socket)
@@ -765,7 +762,7 @@ function onHeadersTimeout (self) {
 function onSocketConnect () {
   const { [kClient]: client } = this
 
-  client.emit('connect', client)
+  client.emit('connect', client[kUrl], [client])
   resume(client)
 }
 
@@ -844,7 +841,7 @@ function onSocketClose () {
     // Retry remaining requests.
     client[kPendingIdx] = client[kRunningIdx]
 
-    client.emit('disconnect', client, err)
+    client.emit('disconnect', client[kUrl], [client], err)
   }
 
   resume(client)
@@ -931,7 +928,7 @@ function socketResume (socket) {
 
 function emitDrain (client) {
   client[kNeedDrain] = 0
-  client.emit('drain')
+  client.emit('drain', this[kUrl].origin)
 }
 
 function resume (client, sync) {
@@ -962,8 +959,9 @@ function _resume (client, sync) {
       continue
     }
 
+    const socket = this[kSocket]
+
     if (client[kSocket]) {
-      const socket = client[kSocket]
       const timeout = client.running > 0 ? 0 : client[kKeepAliveTimeoutValue]
 
       if (socket[kIdleTimeoutValue] !== timeout) {
@@ -985,7 +983,13 @@ function _resume (client, sync) {
       }
     }
 
-    if (client.busy) {
+    const busy = (
+      (socket && (socket[kReset] || socket[kWriting])) ||
+      (this.size >= (this[kPipelining] || 1)) ||
+      this.pending > 0
+    )
+
+    if (busy) {
       client[kNeedDrain] = 2
     } else if (client[kNeedDrain] === 2) {
       if (sync) {